Method and apparatus for making rims for vehicle wheels having pneumatic tires



y 5, 1966 A. SCHU LER 3,258,833

METHOD AND APPARATUS FOR MAKI RI FOR VEHICLE WHEELS HAVING PNEUMATIC TES Filed Dec. 15, 1961 3 Sheets-Sheet 1 Fig. 1

-6f FLANGE 6" 6e RIM aonom //7 van/0r Ar/ur SchU/f/er By his affomeys y5, 1966 A. SCHUTTLER 3,258,833

METHOD AND APPARATUS FOR MAKING RIMS FOR VEHICLE WHEELS HAVING PNEUMATICTIRES 3 Sheets-Sheet 2 Filed Dec. 15, 1961 mum/0r A/fu/ SchU/f/er Byh/saflomeys W AAW y 5, 19 6 A. SCHUTTLER 3,258,833

METHOD AND APPARATUS FOR MAKING RIMS FOR VEHICLE WHEELS HAVING PNEUMATICTIRES Filed Dec. 15, 1961 3 Sheets-Sheet 3 Fig.5

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mum/0 Ar/ur Schu'ff/er By his af/omeys United States Patent Ofiice3,258,833 Patented July 5, 1966 3,258,833 METHOD AND APPARATUS FORMAKING RIMS FOR VEHICLE WHEELS HAVING PNEUMATIC TIRES Artur Schiittler,Solingen-Ohligs, Germany, assignor to Kronprinz Aktiengesellschaft,Solingen-Ohligs, Germany, a corporation of Germany Filed Dec. 15, 1961,Ser. No. 159,528 Claims priority, application Germany, Dec. 15, 1960, K42,394; June 29, 1961, K 44,125 7 Claims. (Cl. 29159.1)

It is known in the art to manufacture rims for vehicle wheels havingpneumatic tires from cylindrical sheetmetal rings by profile shapingdeformation. Such rims produced by means known per se show in all zonesof the profiles a constant wall thickness. The mechaical stresses of thedifferent profile zones occurring in the operating practice, however,deviate considerably from each other. The stresses are substantiallyless in the region of the rim bottom than on the passages to the wheelflanges andin the case of longitudinally divided rimsin the region ofthe annular groove serving to receive the sealing ring.

The object of my invention is to adapt the wall thickness of the rimsmanufactured from metal-sheet rings through a new method to the variablestresses in the different profile zones.

The method in accordance with the invention comprises shaping at firstan axially abridged profile from a sheet-metal ring of correspondingwidth and then stretching said profile out of its natural shape withinthe region of the zone or zones of least stress, in particular in theregion of the rim bottom by reducing the wall thickness. In this manner,the overrating of the rim wall on the lesser stressed zones will beavoided and substantial reduction in weight will be attained with theaid of a very simple stretching-oil method.

The stretching of the lesser stressed zone may be accomplished byvarious means in different ways.

In the first embodiment of an apparatus suitable for accomplishing themethod in accordance with the invention a rigid annular mold having aninner tool movable in the direction of the axis of the mold is provided.

This inner tool may be developed as piston-like drawing tool which canbe introduced into the annular mold in axial direction under pressure.The diameter of this tool is selected so as to form in cooperation withsaid annular mold an annular gap conforming to the desired wallthickness of the zone to be stretched off. The tool is only lowered intothe annular mold to such an extent as the zone to be stretched offreaches and is subsequently withdrawn again.

The same eifect will be attained with a tool using instead of a drawingpiston some rotating pressure rollers supporting mutually, being in samemanner lowered axially into the annular mold, whereby the mountingsupport for said pressure rolls likewise rotates.

A third embodiment of an apparatus particularly suitable foraccomplishing the method in accordance with the invention comprises amandrel fitting into preliminary shaped rim ring having a clampingdevice for said rim ring and an outer tool for stretching off the rimring. As outer tool a drawing ring may be used, cooperating inaccordance with the pattern of a tube jointer bench with the mandrel forstretching off the rim ring. However, it is more appropriate to provideas outer tool one or more stretching rollers parallel to the rotatablemandrel and adjustable transversally thereto.

The FIGURES 1 to represent the afore-described types of embodiments ofthe devices in axial sections.

FIGURES 1 and 2 show an embodiment acting by means of a piston-likedrawing tool before starting and after finishing the stretching-offoperation,

FIGURES 3 and 4 show the corresponding phases of operations whenemploying a rolling tool, whereas FIGURE 5 shows the third type ofembodiment.

According to the novel method, a cylindrical tire ring having flanges ofsubstantially final shape and profile is stretched out axially andsimultaneously its thickness is progressively reduced by expanding onediameter while maintaining the other diameter, as illustrated in thedrawings. In FIGS. 1-4 the inner diameter is stretched and expandedoutwardly while maintaining the same outer diameter, thereby reducingthe thickness of the tire rim. In FIG. 5 the outer diameter is reduced,while maintaining the inner diameter.

On a fixed base plate, e.g., on the table 1 of a vertical press having aslow stroke of the press die, a rigid annular mold 2 is stretched out,serving for the purpose of receiving the rim ring 6. Within the annularmold 2 the table 1 carries an ejector plate 3. On the press die which isnot shown in the illustration, a vertical shaft 4 is supportedconcentrically to the annular mold 2, said shaft carrying on its lowerend the piston-like drawing tool 5.

Rim ring 6 as shown in FIGS. 1 to 4 has a rim bottom 62, flange 6 and anannular groove or rim gutter 6g.

The rim ring 6 is manufactured in a manner known per se, from an annularmetal sheet ring by profile shaping deformation showing an abridgedprofile. Then, the rim ring is inserted into the annular mold (compareFIG. 1). Thereupon, the press die (which is not represented in theillustration) is slowly moved downwardly with the vertical shaft 4thereto attached and the piston-like drawing tool 5. The downwardmovement is finished on the shoulder of the annular groove (compare FIG.2), the rim bottom was stretched-off during the downward motion throughthe contacting edges of the piston-like drawing tool and reaches itsdefinitive width and thickness. After withdrawing the tool 5, the readyformed rim ring 6 is removed from the annular mold 2 with the aid of theejector means 3.

In the embodiment according to the FIGS. 3 and 4 an arrangement ofseveral mutually supporting pressure rolls 7 pivotally provided in arotating disc-like mounting support 8 replaces the piston-like drawingtool. The mounting support 8 connected to a shaft 4 is again connectedwith the die of a press. During the downstroke of the press die mountingsupport 8 turns around its axis in such a manner that the rotatingpressure rolls 7 effect an axial stretching of the profile zone formingthe rim bottom of the rim ring 6.

In the embodiment according to FIG. 5 the rim ring 9 manufactured withabridged profile is set up on a mandrel 10 adapted to the profile moldand rotatably supported in a headstock 11 customary in a stretchingroller device. Through a ring 12 acting on the front side against therim ring 9, the rim ring 9 is clamped on the mandrel 10, whereby thehollow cone 13 of the rim ring 9 in the region of the annular groove 9gfor the rim sealing ring is supported against a cone-like face 14 of themandrel 10. In a slide radius link 15 extending parallel to the mandrel10, a cross slide 16, 17 is movable. The shiftable portion 17 of thecross slide movable transversally to the mandrel 10 carries a stretcherroller 18 on an axis extending parallel to the mandrel 10.

For stretching off the rim ring 9 until attaining the definitive rimprofile represented by dotted lines at 9a, the mandrel 10 with the setup rim ring is rotated by means not shown in the drawing. The portion 17of the cross slide is radially adjusted to the mandrel 10 in such amanner that the distance between the circumference of the stretchingroller and the mandrel conforms to the final thickness of the rimbottom.

Then, the cross slide is moved along the radius link 15 by means knownper se but likewise not represented in the drawing. If manufacturingrims having inclined shoulders 9c is concerned, at the same time withthe shifting in the region of the inclined shoulder a transversal motionof the portion 17 of the cross slide occurs corresponding to the conicalform of the inclined shoulder of the portion 17 of the cross slide, bymeans of controlling and operating means not shown in the drawing.

I claim:

1. A method of manufacturing a rim for pneumatic tired vehicle wheels bydeformation of a sheet metal ring, consisting in first shaping from asheet metal ring of corresponding width an axially abridged rim profilehaving a rim bottom extending axially between an annular groove and aflange in their final form, and then simultaneously stretchingprogressively said rim bottom and progressively deforming and reducingthe thickness of successive portions of the ring bottom by expanding onewall of said rim bottom while holding and maintaining the other wall ofthe rim bottom, whereby the rim bottom profile is brought to its finaldimensions.

2. A method as claimed in claim 1 wherein the original circumference ofthe outer wall is held and maintained.

3. A method as claimed in claim 1 wherein the original circumference ofthe inner wall is held and maintained.

4. A method of manufacturing a rim for pneumatictired vehicle wheels bydeformation of a sheet metal ring, consisting in first shaping from asheet metal ring of corresponding width an axially abridged rim profilehaving a rim bottom extending axially between an annular groove and aflange in their final form, and then simultaneously stretchingprogressively said rim bottom 3 and progressively deforming andexpanding successive portions of one wall of said rim bottom whileholding and maintaining the other wall of the rim bottom andprogressively reducing the thickness of said successive portions,whereby the rim bottom profile is brought to its final dimensions.

5. Apparatus for manufacturing a rim for pneumatic- 5 tired vehiclewheels by deformation of a sheet metal ring, consisting in means forfirst shaping from a sheet metal ring of corresponding width an axiallyabridged rim profile having a rim bottom extending axially between anannular groove and a flange in their final form, and means for thensimultaneously stretching progressively said rim bottom and forprogressively deforming and reducing the thickness of successiveportions of the ring bottom by expanding one wall of said rim bottomwhile holding and maintaining the other Wall of the rim bottom wherebythe rim bottom profile is brought to its final dimensions.

6. Apparatus as claimed in claim 5 wherein the original circumference ofthe outer Wall is held and maintained. 7. Apparatus as claimed in claim5 wherein the original circumference of the inner wall is held andmaintained.

References Cited by the Examiner UNITED STATES PATENTS 25 1,809,6056/1931 Sauzedde 29 159.1 1,826,449 10/1931 BOOth 29-1591 1,922,0888/1933 Hiester 72-115 1,968,296 7/1934 Hiester 72115 2,159,371 5/1939Brink 29-1591 3,029,667 4/1962 Sporck 72-105 3,129,496 4/1964 Cox29-45901 3,181,329 5/1965 Sporck 72---85 5 JOHN F. CAMPBELL, PrimaryExaminer.

NEDWIN BERGER, Examiner.

THOMAS H. EAGER, S. C. KAHLER,

Assistant Examiners.

1. A METHOD OF MANUFACTURING A RIM FOR PNEUMATICTIRED VEHICLE WHEELS BYDEFORMATION OF A SHEET METAL RING, CONSISTING IN FIRST SHAPING FROM ASHEET METAL RING OF CORRESPONDING WIDTH AN AXIALLY ABRIDGED RIM PROFILEHAVING A RIM BOTTOM EXTENDING AXIALLY BETWEEN AND ANNULAR GROOVE AND AFLANGE IN THEIR FORM, AND THEN SIMULTANEOUSLY STRETCHING PROGRESSIVELYSAID RIM BOTTOM AND PROGRESSIVELY DEFORMING AND REDUCING THE THICKNESSOF SUCCESSIVE PORTIONS OF THE RING BOTTOM BY EXPANDING ONE WALL OF SAIDRIM BOTTOM WHILE HOLDING AND MAINTAINING THE OTHER WALL OF THE RIMBOTTTOM, WHEREBY THE RIM BOTTOM PROFILE IS BROUGHT TO ITS FINALDIMENSIONS.